(1) Field of the Invention
The present invention relates to an apparatus for identifying produce which is used to detect positions of produce relative to a produce handling machine and to derive control data for guiding a manipulater, and a guide apparatus for the produce handling machine equipped with the produce identifying apparatus.
An article of fruit hereinafter referred to is inclusive of various fruits, vegetables, nuts and the like, i.e. products of agriculture and horticulture.
(2) Description of the Prior Art
This type of produce identifying apparatus binarizes image data according to the color of fruit to be identified in order to remove the data irrelevant to the fruit, and detects positions, sizes, centers and so on of the fruit on the basis of the binarized image data. Since the image data is binarized according to the color, where a plurality of fruit are growing close together or one behind another to appear like one lump, the apparatus tends to identify the lump as one fruit. It is difficult to separate a plurality of fruit growing close together after binarizing their image data according to the color. Thus, the image data binarized according to the color alone does not readily allow a plurality of fruit to be identified separately.
Consequently, where, for example, the center of the fruit is used in accordance with the binarized image data of the plurality of fruit as a control parameter for determining a guiding direction of a manipulator, the manipulator is guided in a direction deviating from the center of an actual target fruit. This method, therefore, has the disadvantage of causing operational errors.
In order to separately identify a plurality of fruit growing close together and having the same color, it is conceivable to photograph this target fruit as a variable density image corresponding only to their luminance variations, select and binarize only portions of the variable density image data having great luminance variations, and detect edges in the luminance variations. In this case, however, the photographed image includes irrelevant data relating to branches, leaves and the like. Because of the presence of these irrelevant data, the image data corresponding to the target fruit cannot be located by binarizing the entire variable density image data. This method has the further disadvantage of long processing time since a great amount of data must be processed for the edge detection.
Thus, binarized image data for each of the plurality of fruit cannot readily be obtained by either one of the means for binarizing the image data according to the color and the means for binarizing the variable density image data according to the luminance variations. Furthermore, as noted above, the edge detection process for the entire variable density image data is time-consuming and impracticable.
It is possible to separately detect fruit growing close together and appearing in a lump by using both the image data based on the color and the variable density image data. However, this would complicate the apparatus since the edge processing is indispensable.